Talk:SCART/Archive 1

Archive 1

Archive 2

Speculations about SCART introduction reasons

There's a whole section of speculations and claims about French legislation that are not supported by any references, which would normally be quite easy (legislation and regulations are indexed). David.Monniaux 08:52, 22 Apr 2004 (UTC)

Strangely, There is much truth in this (I note the reference has been removed). France has always had a particularly repressive government - extremely socialist verging on communist. The original French TV standard (the 819 line system) was introduced for two reasons. First: to prevent French citizens from watching unsuitable television broadcasts (i.e. anything not originating from the heavily government controlled French station). Second, to protect French television manufacturers from foreign competition as the 819 line system was a patented proprietary system.

When France moved to colour, it had to abandon the 819 line system as the bandwidth requirements were unacceptable. It was long speculated that the French SECAM colour system was to similarly discourage viewing of 'unsuitable material', but in fact the SECAM colour system was developed before the PAL system, used by the rest of Europe - and France hoped to sell it to the remainder of Europe. (Interestingly, the USSR adopted SECAM for precisely this reason.) France adopted the now European standard 625 line system, but adopted an inverted form of the system to prevent French televisions from receiving 'unsuitable broadcasts'. France used a system of positive video modulation, whereas the rest of the world had adopted negative modulation which was far less prone to breakup due to interference.

French guy here. Wut?

Hey! How do you know this is not just coffee machine ranting? Adam Mirowski 05:08, 22 October 2006 (UTC)

It is. There was never anything to stop Belgium, Luxembourg or Monaco making "unsuitable broadcasts" on 819 lines. And there were times when they did just that ! —Preceding unsigned comment added by 213.40.129.129 (talk) 18:56, 24 November 2008 (UTC)

French analogue satellite broadcasts used a system called DMAC2 for much the same reason (though DMAC was actually a British development). With the introduction of Video Recording, the French developed the SCART interface and legislated that all French Televisions and Video recorders had to be fitted with the connector. The idea was to once again protect the French television and video industry from foreign competition as the connector was proprietary. Unfortunately for the French, the idea of having a single connector and cable to connect all the audio and video signals for recording and playback in one go was such a good one (even if the connector itself left a lot to be desired), that it was rapidly copied throughout Europe. So much so that the French were unable to launch patent infingement suits on the required scale.

Conspiracy theories forever! Adam Mirowski 05:08, 22 October 2006 (UTC)

Even today, the French are having to live with a digital TV system that is incompatible with the rest of Europe. The internet itself caused much panic in Paris, when the government heavily tried to discourage its use, and tried to pursuade French citizens to use the obsolete (but government controlled) Minitel system instead. I B Wright 16:10, 21 October 2006 (UTC)

Damn! You almost looked serious when I started reading this. Adam Mirowski 05:08, 22 October 2006 (UTC)

What is component video, really?

"RGB signals, which were SCART's strong point for many years, are getting less useful today, after the (arguably) superior component video signal format was introduced", I thought RGB was a type of component video ?

There are differing definitions of "component video". Some use it to mean "S-Video", i.e. luma and chroma separately, while others use a wider definition that includes RGB. I can't think of any reason for claiming that S-Video is "superior" to RGB, though. -- Heron 19:38, 10 May 2004 (UTC)

S-Video is not (RGB is better). However, YUV can beat RGB/SCART since it's been used for progressive scan content, and higher resolution content.

Ah. I have just done some reading, and I have found that another, and perhaps the correct, definition of "component video" is Y-Cb-Cr video (i.e. luma and the two quadrature components of chroma). This explains the statement "SCART cannot carry component video" in our article. I don't think this format is superior to RGB in terms of pure quality, but it makes more efficient use of bandwidth and is probably more than good enough for TV viewing. -- Heron (again)

YCbCr is not superior in any way. For all practical purposes, the two can be considered identical. The signal on a DVD or transmitted by digital television is YCrCb. The signal required by the display device, be it a CRT; Plasma or LCD display is RGB. The former has to be converted to the latter at some point in the chain and it does not matter whether this occurs in the DVD player or the digital TV set top box, or in the television set itself. To be really accurate, YCbCr has problems if it is to be carried over very long distances, because the CbCr components have a much narrower bandwidth than the Y component. Differing propagation coefficients of the signals will cause the colour information to arrive ahead of the luminance information. However, it does require a very long distance to make this effect noticeable. I B Wright 15:36, 21 October 2006 (UTC)

Also I would think the skew corrections for RGB would be a bit easier than for YCbCr - all you need are alternating black & white lines and to tweak the delays so they don't have colour fringes. Having to alter where two different less obvious colour components lie either side of a luminance change would be more complex... 193.63.174.210 (talk) 18:35, 24 October 2008 (UTC)

"Component video" by definition refers to any method of transmitting video signals in components, as opposed to composite video where it is all in the one line. Therefore, "component video" refers to either RGB, any forms of colour difference component (YUV, YPbPr, YCbCr, etc.) or S-Video. Saying it only refers to one of the above is incorrect, and just bad English. --Zilog Jones 18:31, 16 August 2005 (UTC)

Although you are correct, S-Video is not considered a component video system, because the chrominance wire does not carry a component, but rather the 2 colour difference signals quadrature modulated onto the suppressed colour sub-carrier just like CVBS (composite video). I B Wright 15:36, 21 October 2006 (UTC)

SCART should be innovated

SCART is a very good type of multipurpose audio/video cable but it has become rather large. Why don't they change the connector to something with smaller pins, closer to each other (ie the DVI pin layout). In addition with the new connector more pins could be added to carry more signals/cables. An adapter could also be created to still be able to plug the cable into a normal SCART connector. my 2 cents, Stef Nighthawk.

I've knocked off 'So it is difficult to argue with the no-import rationale above' from the end of the speculations bit because it's irrational. It essentially presents the second suggestion as a straw man.

Personally, I think that whole section is silly.

The pins are further apart to prevent cross-talk, and therefore increase picture quality. DVI/HDMI Cables have the pins closer together because Digital Cables are less prone to cross-talk and so picture quality does not suffer.

MORE: Quite a few set-top box manufacturers have elected to use smaller connectors, particularly on the back of digital STBs, where the mini-DIN has been used. This of-course requires a special lead to connect to the TV's standard SCART socket. Manufacturers I can think of who have gone for this approach include Amino Communications and Video Networks' HomeChoice boxes. A disadvantage of this aproach is that the thick cables needed for good-quality video and audio can put a lot of strain on such small connectors. I believe they have chosen different pin-outs, too. — Kim SJ 12:10, 22 August 2006 (UTC)

This, unfortunately, isn't a new obsession though; I have 1980's home entertainment gear that uses mini-DIN's which could either be used direct to connect to other gear by the same maker, or through nastily huge adapters for RCA or SCART. None of them seem to let you output RGB over them either. --Kiand 12:14, 22 August 2006 (UTC)

Are you sure about this crosstalk thing ? The VGA cnnector used by most analouge computer monitors uses a far narrower pin spacing and Im not aware of any crossralk issues (no sound though).

1. "Become" rather large? It was ALWAYS this size. Everything else has just got smaller. Whether it got better - or at least, whether it would be better at carrying the exact same signals - is another thing entirely.

2. On multi-way mini-DIN things ... I think you may find on closer inspection they only carry Composite, S-Video, and stereo sound. Unless they have a hueg number of pins or offer a pretty clever switching arrangement (and no seperate grounds for each of the colours), there's no RGB or component there. I've only, personally, ever seen those implemented as SCART, multi-phono, full DIN (with lots of pins) or DB-15HD (ie VGA), sometimes with converters between them - e.g. to pipe a SCART RGB or YCrCb signal down a VGA + 3.5mm audio minijack into a data-projector.

3. VGA crosstalks and degrades like a motherf****r at noticably lower distances than SCART - though admittedly it does also tend to operate at much higher resolutions and scan rates, and again often uses cheaper cable (ever notice that you get "thin" and "thick" VGA cables? Tip: don't use LONG "thin" cables... again it comes down to the in-cable shielding levels). It's not really meant for that kind of thing, 6 to 12ft is your practical maximum before suffering slight degradation. Beyond that, it's a better idea to split it to multiple seperate-phono or BNC (allowing seperate shielding) for each of the major signals (RGBHV) and use converters at one/both ends as necessary. Or CAT5 with devices to allow you to connect for differences in run length for really long cables.... and to do similar for SCART or even S-Video if you want to go great distances. There's a good reason composite was used for broadcast rather than putting components on different frequencies :) 193.63.174.210 (talk) 18:31, 24 October 2008 (UTC)

"VGA crosstalks and degrades like a motherf****r at noticably lower distances than SCART": I don't think VGA crosstalk issues have anything to do with the connector. If they did they would be an issue even on short cables. You do need a good quality impedance controlled cable to run VGA a long distance with decent quality but that would apply regardless of the connector.

"There's a good reason composite was used for broadcast rather than putting components on different frequencies :)" yeah, they wanted to cram a color picture into the frequency space intended for black and white TV. Plugwash (talk) 03:38, 26 December 2008 (UTC)

Yeah... I'm not 100% sure on where I was going with that. Maybe got a bit confused. I think the point was supposed to be that domestic/office VGA connections tend to be using quite short cable runs - a flimsy (relative to SCART only!) socket, thin pins and with the requisite thin, less well shielded wiring that would be needed to physically hook up said pins, plus the lower voltage levels trying to drag the signal through all that is perfectly fine at a short distance, but starts needing extra help once you go beyond a few metres. For moderate runs you can get away with (expensive) fully-shielded, oxygen free, impedence balanced cable, but I wouldn't much trust anything more than 10m (though I've seen up to 35m sold - presumably for use with a signal booster in-line?). After that you'll see professional installs running 5-way BNC or CAT5 converters instead to fight degredation. However I'll admit I have no idea how far SCART can be successfully run, other than I haven't yet found the limit. Higher voltage, typically better shielding - and fatter pins and chunkier socket to allow this to be properly soldered in, including termination resistors in proper good-quality examples. You could probably do that with VGA, DVI, HDMI, but it would definitely have to be a solid state arrangement, possibly with an IC involved somewhere. I have a feeling that's one reason for Apple's Mini-DVI/Mini-Displayport to VGA adaptors being so incredibly short. ((However, for long runs, the well-shielded, balanced, high grade Composite still takes the cake, if you only want broadcast-level video; for hi-def, better to go all-digital)) ......... As for the different frequencies thing... err... that's prolly something to do with them all being on the same carrier and therefore not being able to go out of phase or have much crosstalk influence on each other (besides what is inherent in the composite method anyway). Whereas long runs of seperate cable can have problems where each signal takes different lengths of time to arrive. Yeah. It had probably been a very long day and my mind was wandering :p There was a point to be made, but like a digital signal that's become too weak, all hope of recovery is lost. 193.63.174.10 (talk) 17:49, 10 February 2010 (UTC)

-- gah --

After a while of being a little unsure on it but thinking I had a handle on the basic ideas behind video over CAT5 (etc), I went off and looked it up after participating in this mini board. Proved quite hard to find, but, conclusion: Disregard all the above, don't even try to argue back against it :D ... turns out the benefits are largely that of using twisted pair cable with differential signalling (vastly reducing the effects of outside interference, even WITHOUT using shielding (STP merely makes it "even better"), and electrically isolating the sender and receiver to avoid ground loops (50/60Hz buzz can be a killer for video signals, particularly those running at a different frequency). And there I thought it was just because it was high quality cable - actually, as the song goes, It's All In The Baluns. 193.63.174.10 (talk) 18:34, 10 February 2010 (UTC)

Not true

The article states that "In general, 5.1 sound is new to European TV, it only started to appear in 2004, on selected satellite channels."

This is not true, as for example some German TV Stations, ProSieben for example, started broadcasting Dolby Digital via Satellite, and I think Digital Cable (sic, satellite AND cable - another correction to the article), at least around 2002, maybe even earlier. thanks, --Abdull 20:16, 17 Jan 2005 (UTC)

And what about DVDs and LaserDiscs, which have had surround sound for many years? Things that aren't broadcasted can use SCART cables too! --193.1.100.105 10:37, 29 Mar 2005 (UTC)

I've removed that, as it was both incorrect and irrelevant - whether 5.1 is new or not, the lack of it is still a drawback. TerokNor 16:08, 26 Jun 2005 (UTC)

I would guess the person that wrote that was British, as 5.1 has only been available on TV in the UK since 2004 unless you were getting foreign satellite channels... *hugs his Comag*. --Kiand 21:24, 16 January 2006 (UTC)

IMHO there's a problem with the related drawback "SCART is limited to two audio channels - meaning it cannot deliver true surround sound", AFAIK it can deliver surround sound in matrixed forms (ie. ProLogic), which from my standpoint is as true as any other form. I believe true should be changed to discrete, but correct me if I'm wrong. --Outlyer 16:32, 3 July 2006 (UTC)

Yes, fair point - but it's still not "5.1" as originally stated, is it. That term implies discrete 6-channel audio, distinct from, say, a 2.0 channel Dolby Prologic signal (that becomes 3.0 or 4.0 post-decoding dependent on version) which offers pseudo-surround sound in much the same way that an "full colour" anaglyphic (red & green glasses, but with weaker tints in this case) movie offers 3D images. 193.63.174.210 (talk) 18:22, 24 October 2008 (UTC)

New pinout table

I propose a proper pinout table is added to this page. The list now is a bit hard to read, and confusing, as certain pins have different assignments whether the signal being transmitted is RGB, composite or s-video. Also, signal levels and impedance should be listed too. I suggest using this from pinouts.ru as a template for this - they don't seem to mention anything about copyrights or licenses, so I assume it's free imformation.

I have to find out how to do tables properly first, but I was thinking along the lines of this for the rows:

pin | audio | CVBS (composite video) | RGB | S-video (Y/C) | Other

And another table for voltages/impedance for each pin. This is an important issue, especially with RGB as some devices output 1V RGB and others output .7V. --Zilog Jones 15:07, 1 Apr 2005 (UTC)

D²B (Digital Data Bus) -- Possibly incorrectly named.

I couldn't find Digital Data Bus on the IEC website, but I could find domestic digital bus (D2B)

The standards are:

IEC 60933-4 
IEC 61030
IEC 61030-am1

Could someone confirm if this is correct.

Further research suggest that the bus may now be called "Av.Link". "Av.Link" Is defined by the following standard:

EN 50157

The "Av.Link" info was gleaned from the following sources:

http://www.digitaltelevision.gov.uk/pdf_documents/publications/SCART_report_issue.pdf
http://fmt.cs.utwente.nl/Docs/publications/files/111_heerink.pdf
http://www.dtg.org.uk/publications/books/connectivity_guidelines.pdf

Also, the IEC link brings up too many hits. (The correct one being "International Electrotechnical Commission") --Redrob 23:20, 10 Jun 2005 (UTC)

Specifications, and names.

The SCART connector is formally called the "peritelivision connector"

I Believe the standard defining the scart is:

IEC 60807-9 (Rectangular connectors for frequencies below 3 MHz - Part 9: Detail specification for a range of peritelevision connectors)

And also the following British & European standards:

EN 50049-1
BS EN 50049-1
BS EN 50157-1

The source for this info (and an interesting document in it's own right) is this pdf file:

http://www.digitaltelevision.gov.uk/pdf_documents/publications/SCART_report_issue.pdf

--Redrob 23:00, 10 Jun 2005 (UTC)

Right... and it copies entire sentences from our Wikipedia SCART article. I know it copies because I wrote them originally. But it does improve the content.

Remember the rules kids - once something is cited in an official or third party printed document or online PDF, it's officially true. Even if it came from Wikipedia in the first place because the author was feeling lazy. Therefore we can now quote the original text back into the article as cited material instead. Logical and ontological paradoxes? Hah! We spit at them. 193.63.174.210 (talk) 18:18, 24 October 2008 (UTC)

The speculation section

The speculation section at the end of the article does not conform to NPOV or standard formating for Wikipedia articles. The italicized comments at the beginning are NPOV. Arguments for and against this speculation can be presented but should be sourced. Evidence said to discount this speculation can be presented but only in a NPOV manor in which the article does not appear to take sides. --Cab88

I'd remove that section ASAP, its a real mess and adds nothing to the article! EAi 19:10, 14 November 2005 (UTC)

BLOCKED USER: {dark radar} 25 monkies aside --- the error felt like a scart connection, then on research introspection, i noticed the 'locking' capability this had given itself to (lindy) in my introversion i have found scart to be Ulysees-Invention as much as he is can become a 'loch pirate' as-well, scarts were invented as a compromise/comprisory because of the same jaen misfunction of INRI - those that know SPQR at this symbol mysogeny,, scart laymen see loch-like translation, dimmer switch intervention, [o reader grappling],, computers - though do not like locking devices, including lock-break-switiching-circuits, which the internet is going through right now, they tend to like IO definite things, so scarts as they do 'crack',, it is the joystick i can say at this point of intervention that holds the key of a certain resonant symbology to iron out these ruffians... —Preceding unsigned comment added by 86.156.28.29 (talk) 16:16, 24 April 2008 (UTC)

Wow.... just, wow. Whipped cream for your word salad, sir? 193.63.174.10 (talk) 17:33, 10 February 2010 (UTC)

Clarify direction of input and output

An anonymous contributor has added (14:08, 14 April 2006) that "Input and output are defined with respect to the TV set". I believe that the directions stated in the article apply to ALL sockets and that the SCART cable will "cross over" the connections. -- Nick 17:03, 14 April 2006 (UTC)

In my experience at least, 'standard' (fully-wired or composite+audio only) SCART cables swap pins 19 and 20, ie composite input and composite output are swapped. If you are constructing a SCART-enabled device you have to use pin 20 to output composite video (or the composite sync if you're using RGB) and the cable then ensures that it is correctly fed into the 'composite input' pin when you connect it to a television. So yes, you're right, it's defined with respect to all sockets. Knowing this would have saved me much confusion when my picture wouldn't hold sync! [with apologies for anonymity]

Would it be simplest to describe it as "input/output" being relative to each DEVICE, given that the sockets have to be mounted on it anyway - but each socket can still be ambiguously described much as each cable plug can, depending which direction you look at it, whereas a TV, VCR, etc has a fairly definite "inside" and "outside". Then it's a fairly standard affair (in terms of cabling), similar to how RS232 and the like function. The output sub-socket of device A hits pin X of the cable that's plugged into it, whose internal wire crosses over with another, to reach pin Y at the other end - feeding the input sub-socket of device B. EG the composite output from your VCR flipping over to hit the composite input of the TV. For the signals that each have orthogonal pairings (ie Composite, L/R audio, and in some cases S-Video), this is a permanent arrangement. RGB/blanking/activity tends to be hardwired one-way, no crossovers, because the only item that tends to pay them attention is a television set (few recording devices can do anything useful with anything except composite - indeed, RGB in AND out is meaningless with VHS decks), and in this case all of device A's connections for it will be "output", and all of device B's will be "input". B can still send basic video back down the line to A if desired (e.g. decoded DVB-T images for recording on a non-digital-compatible VCR), so it's not exactly crippled.

This is why you need to pay attention to the "up" and "down" stream labelling (typically "TV" and "Satellite" or "VCR") on twin-socket decks, incidentally - the basic signals can go either way, but it will only pass-thru RGB, activity, etc from down to up (or VCR/Sat to TV), automatically switching off it's own outputs if necessary (for example, a games console feeding through a VCR and Cable box to a TV --- the RGB feed from the console will happily go up through to the TV, and the composite signal from the VCR box; the video can also pick up composite video from the cable box, though it does block anything coming down from the TV unless the power cord is yanked - this isn't a problem except in the very rare, five-nines case where there's something you want to record, on a digital channel, and the cable has died but Freeview is still transmitting (or, you want to watch a cable-only channel whilst recording freeview)... in which case you quickly grab a SCART-RCA lead and patch the TV's second SCART output feed into the VCR's yellow red 'n' white front panel, tune the digital receiver, and relax ;) ... the rest of the time it's actually more useful as you can record from cable whilst watching something else on freeview). 193.63.174.10 (talk) 17:24, 10 February 2010 (UTC)

---

re: "RGB connections are not bidirectional. Bidirectional S-Video was added in an extension, although few devices support this, so downstream connections are almost always composite.". Shouldn't this say "upstream"? Blue Basin 49 22:57, 29 October 2006 (UTC)

I do wonder if whoever labelled "Red(Green, Blue) Up/Down" on the diagram got confused and meant Signal and Ground (or more accurately, "Return") - it wouldn't be too fanciful to imagine each colour line has a seperate return loop to prevent crosstalk, the same as VGA and Component RCA / BNC. Bidirectional RGB could be implemented using those return lines (much like a telephone loop), but it would be quite noisy and suffer a lot of interference between the two images, a bit like old school analogue cable TV when they tried to squeeze too many channels down the same line... 193.63.174.10 (talk) 17:24, 10 February 2010 (UTC)

drawbacks

seems this unsourced anti-Péritel section is a bit too much. was it done by an english or a republican or some? :) "the connector is too bulky compared to the american VGA?" WTF? why not stating "the RCA connector is cute compared to the Péritel?!"... to say the SCART doesn't allow dolby digital EX ouput is just as stupid as to compare the old Péritel with the VGA scart. are you stupid? these stuff came 20 years later, you cannot compare obsolete technologies with the current standard and call them drawbacks, it doesn't make sense. by the way the shitty RCA cannot be compared with the latest optical TOSLINK for DTS neither, nor the VGA technology. i remember the british (and possibly the aussies too) had a state of the art "RF unit" to connect their pal sega game console through the antenna roof connector :D when we had a secam model with Péritel RVB (RGB SCART) in the 80/90s. it is unfair to compare PERITEL with other stuff than original RCA and Mini-DIN (ushiden). same thing for the cable, you can note many drawbacks with the RCA cable, cheap, thin, too long, fragile, etc. Péritel is a good technology it's just greedy people tend to buy 1€ cheap 5-meter coax cables from china and use these long cables instead of the short (lighter) models. Personally i like the Péritel because i did not had that much drawbacks. the only pin that broke up happened with a 10-pin connector from china or japan. french 21-pin (the original french was 21 not 10) connectors are more expensive but more solid. anyway cheap RCA connectors have drawbacks too, i've experienced plugging a male video RCA connector in a female socket and the whole female socket came with the male (she must be in love or some) when i've unplugged the cable, so what? is it worthy to make a section about this stuff? drawbacks can happen with cheap cables but it's up to the chinese maker (non-standard quality) not to the original design or standard models. how many people with a 10-pin SCART cable or adaptator know they will never reach RGB but will get a shitty CVBS picture instead. these people would cry EUROSCART are shit but this has nothing to do with the genuine Péritel! even the article's top picture is a cheap connector, "Champion" what's that? the musketeers of the distribution... Paris By Night 20:37, 4 January 2007 (UTC)

That was a little bit loony, but on the whole I agree. Particularly the late point about how "Cinch" sockets seem to bond more tightly with the plugs that go into them than their own motherboards. SCART may be weak against heavy cables or other angular pressure / stretching / etc, but at least when it does pop out of the socket under this strain it doesn't destroy your TV and prevent you plugging it back in... it merely makes you think a little more about how you arrange your cables in order to prevent it (e.g. maybe cable-tying them to one of the convenient loops that get provided on the back of TV sets?). Which is something I HAVE seen more than once, including on expensive and often uneconomic-to-repair video projectors ... which I think tend to omit SCART plugs almost out of spite - or, to sell expensive VGA/component converters and because they know the other connectors are more vulnerable to the type of abuse these devices will often suffer, and how much their own service departments charge to repair them. Argh. 193.63.174.210 (talk) 18:42, 24 October 2008 (UTC)

Expert tagging

section title abbreviated from

Who's so expert so as to decide that "This article or section is in need of attention from an expert on the subject"? // FrankB 16:09, 10 April 2007 (UTC)

Obviously those who added to the article's contents possess considerable expertise. The article is well written and informative. What was the intention of whoever attached such a tag? To make Wikipedia a treatise on Electronics, among about other sciences? Preposterous! --AVM 20:17, 19 March 2007 (UTC)

• Well, I'm expert enough to figure out you have a good point... alas, tis just 'yet another' cleanup tag sans date thereafter ignored by the editor who should have been monitoring it's progress in the nearly a year since. As such, I'm removing that. // FrankB 16:09, 10 April 2007 (UTC)